Question: Omar starts counting at 28, and he counts by threes. If 28 is the 1st number that Omar counts. what is the 14th number that he counts?
Solution: What is the first number that he counts? $28$ What is the second number that he counts? $\begin{align*}&28 + 3 \\ &= 31\end{align*}$ What is the third number that he counts? $\begin{align*}&28 + 3 + 3 \\ &= 28 + (2 \times 3) \\ &= 34\end{align*}$ What is the 14th number that he counts? $\begin{align*}&28 + (13\times3) \\ &= 28 + 39 \\ &= 67\end{align*}$